Conventionally, when clothing is washed at homes or at coin laundromats where a plurality of washing machines is provided, washing is performed by using detergent. However, surfactants in synthetic detergents are known to cause skin stimulation or allergy as well as environmental concerns. Accordingly, Yamaji et al. (Japanese patent publication No. 2003-144793) discloses a washing apparatus that alleviates environmental pollution by using alkaline water and acidic water ionized by electrolyzed saline solutions to reduce the need for detergents.
However, the apparatus described by Yamaji requires the installation of a saline solution tank and an ionized water generator for electrolysis. Therefore, the apparatus is disadvantageous in that the salinity may cause rusting on the peripheral and installation of the ionized water generator may result in complications and enlargement of the apparatus.
On the other hand, it has been known that alkaline ionized water with high alkalinity exhibits high washing performance and provides sufficient washing capacity with little or no detergent required. It has also been known that alkaline ionized water neither causes skin stimulation or allergy nor leads to environmental pollution. However, it has been difficult to supply alkaline ionized water with highly stable alkalinity.